vacuum advance testing procedure?

[Dutchboy]

Ive been finally chasing some problems on the ole accord and the shop manual off pauls site is so vague on the testing procedure on the vacuum advance...and my stupid manual doesnt say anything at all how to test it..

I am almost positive that both ports have to hold 20in/hg of vacuum but it doesnt say this directly and all the pictures show them holding vacuum on the cold advance side and not the normal running side.

my advanvce holds vacuum on only one port so i need to have conformation on this.....

Do both ports have to hold 20in of vacuum??????

[A20A1]

Both ports should hold vacuum

However as long as #2 holds vacuum your okay for your vacuum advance, cept if you have cold start problems... then #25 should be working too. #25 is cut off from vacuum when the thermovalve senses the coolant is hot enough.

[McNick]

And how to check the centrifugal advance mechanics?
When I disassembled the dizzy I founded that the one of two weights is turning on axle with force more than other one. How much is this critical for timing?
Does anybody know the curve of "RPM/Centrifugal advance effect on timing" for A20Ax?

[Dutchboy]

well the #25 is always getting vacuum so i just plugged it for now... the little thermovalve is not working on my car

#2 is getting vacuum okay but the diaphram wont hold a vacuum.... it does still advance it but the way it is it leaks down and is creating a vacuum leak...

So i guess i order a new advance toady and mabye itll fix my stumble then!! I also jsut found another vacuum leak on my #24 line for the air suction which isnt even there anymore either.....im slowly fixxing the ole girl!! she hasnt run this good for a long time

Thanks for the help.. someone should clarify this by putting it in the how to for others to know!

[sonusa]

Which thermo valve you found not working I think I have same kind of problem